When a suspicious tissue mass is discovered in a patient's breast through examination, ultrasound, MRI, X-ray imaging or the like, it is often necessary to perform a biopsy procedure to remove one or more samples of that tissue in order to determine whether the mass contains cancerous cells. A biopsy may be performed using an open or percutaneous method.
An open biopsy is performed by making a large incision in the breast and removing either the entire mass, called an excisional biopsy, or a substantial portion of it, known as an incisional biopsy. An open biopsy is a surgical procedure that is usually done as an outpatient procedure in a hospital or a surgical center, involving both high cost and a high level of trauma to the patient. Open biopsy carries a relatively higher risk of infection and bleeding than does percutaneous biopsy, and the disfigurement that sometimes results from an open biopsy may make it difficult to read future mammograms. Further, the aesthetic considerations of the patient make open biopsy even less appealing due to the risk of disfigurement. Given that a high percentage of biopsies show that the suspicious tissue mass is not cancerous, the downsides of the open biopsy procedure render this method inappropriate in many cases.
Percutaneous biopsy, to the contrary, is much less invasive than open biopsy. Percutaneous biopsy may be performed using fine needle aspiration (FNA) or core needle biopsy. In FNA, a very thin needle is used to withdraw fluid and cells from the suspicious tissue mass. This method has an advantage in that it is very low-pain, so low-pain that local anesthetic is not always used because the application of it may be more painful than the FNA itself. However, a shortcoming of FNA is that only a small number of cells are obtained through the procedure, rendering it relatively less useful in analyzing the suspicious tissue and making an assessment of the progression of the cancer less simple if the sample is found to be malignant.
During a core needle biopsy, a small tissue sample is removed allowing for a pathological assessment of the tissue, including an assessment of the progression of any cancerous cells that are found. The following patent documents disclose various core biopsy devices and are incorporated herein by reference in their entirety: U.S. Pat. No. 6,273,862 issued Aug. 14, 2001; U.S. Pat. No. 6,231,522 issued May 15, 2001; U.S. Pat. No. 6,228,055 issued May 8, 2001; U.S. Pat. No. 6,120,462 issued Sep. 19, 2000; U.S. Pat. No. 6,086,544 issued Jul. 11, 2000; U.S. Pat. No. 6,077,230 issued Jun. 20, 2000; U.S. Pat. No. 6,017,316 issued Jan. 25, 2000; U.S. Pat. No. 6,007,497 issued Dec. 28, 1999; U.S. Pat. No. 5,980,469 issued Nov. 9, 1999; U.S. Pat. No. 5,964,716 issued Oct. 12, 1999; U.S. Pat. No. 5,928,164 issued Jul. 27, 1999; U.S. Pat. No. 5,775,333 issued Jul. 7, 1998; U.S. Pat. No. 5,769,086 issued Jun. 23, 1998; U.S. Pat. No. 5,649,547 issued Jul. 22, 1997; U.S. Pat. No. 5,526,822 issued Jun. 18, 1996; and US Patent Application 2003/0199753 published Oct. 23, 2003 to Hibner et al.
At present, a biopsy instrument marketed under the trade name MAMMOTOME is commercially available from ETHICON ENDO-SURGERY, INC. for use in obtaining breast biopsy samples. This device generally retrieves multiple core biopsy samples from one insertion into breast tissue with vacuum assistance. In particular, a cutter tube is extended into a probe to cut tissue prolapsed into a side aperture under vacuum assistance and then the cutter tube is fully retracted between cuts to extract the sample.
With a long probe, the rate of sample taking is limited not only by the time required to rotate or reposition the probe but also by the time needed to translate the cutter. As an alternative to this “long stroke” biopsy device, a “short stroke” biopsy device is described in the following commonly assigned patent applications: U.S. patent application Ser. No. 10/676,944, “Biopsy Instrument with Internal Specimen Collection Mechanism” filed Sep. 30, 2003 in the name of Hibner et al.; and U.S. patent application Ser. No. 10/732,843, “Biopsy Device with Sample Tube” filed Dec. 10, 2003 in the name of Cicenas et al. The cutter is cycled across the side aperture, reducing the sample time. Several alternative specimen collection mechanisms are described that draw samples through the cutter tube, all of which allow for taking multiple samples without removing the probe from the breast.
The vacuum assistance presented at the side aperture provides a further benefit of reducing the accumulation of bodily fluids around the probe that may tend to interfere with taking a diagnostic image, may impede subsequent insufflation and marker deployment, leave an undesirable hematoma at the biopsy site, and/or result in external bleeding that is a biohazard and may increase the patient's discomfort.
While the vacuum assistance has a number of benefits, some practitioners prefer to perform core biopsy procedures with simpler devices that do not include a control module with graphical user interface, electronic control, vacuum generation and control, and other features. In addition to the desire to reduce capital costs, it is also generally desirable to reduce the need to tether a hand-held biopsy device to sources of mechanical motion, vacuum supply, electrical power and control. Such tethers may tend to impede positioning of the biopsy device, introduce tripping hazards, and increase set up time.
Therefore, while these multiple sample core biopsy instruments have numerous advantages, it is believed that the diagnostic and therapeutic advantages of the core biopsy procedures would be seen as more desirable if vacuum assistance could be incorporated in a more convenient manner.